Safety switch for mechanized files



Feb. 19, 1963 B. w. WOODWARD ETAL 3,077,967

SAFETY SWITCH FOR MECHANIZED FILES Filed Sept. 24, 1959 3 Sheets-Sheet 1BENdAM/N W WOODWARD WALTER G. ANDERS ATTORNEYS Feb. 19, 1963 B. w.WOODWARD ETAL 3,077,957

SAFETY SWITCH FOR MECHANIZED FILES Filed Sept. 24, 1959 3 Sheets-Sheet 2FlG.3

RESET (Rs) MA CH/NE FRAME\ /1;

INVENTORS BENJAMIN W- WOODWARD WALTER W ANDERS BYZZI I fiMJ-W A TTORNEYSFeb. 19, 1963 B. W. WOODWARD ET AL SAFETY SWITCH FOR MECHANIZED FILESFiled Sept. 24, 1959 3 Sheets-Sheet 3 POSITIVE (RED) COMMUTATOR ASSEM.

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3,077,367 SAFETY SWiTCH FGR MEQHANIZED FILES Benjamin W. Woodward andWalter G. Anders, Kenmore, N.Y., assignors to Sperry Rand Corporation,New York, 'N.Y., a corporation of Delaware Filed Sept. 24, 1359, Ser.No. 842,086 7 Claims. (Cl. 192--130) This invention relates tomechanized files and more particularly to an endless conveyor filehaving a plurality of card trays mounted to travel in an endlessvertical path within the file casing. In devices of this type the traysare moved to a reference position wherein the tray desired is disposedin front of the operator at an open upper portion of the file casing.

The main object. of the invention is to. provide a simple, efiicient andeconomical construction of switch which is located adjacent thereference position sothat the machine is stopped whenever the hand ofthe operator comes in contact with the switch bar especially when thetrays are in motion. This is obviously to prevent injury to the hand ofthe operator if it is extended too far into the casing, especially whenthe trays are in motion.

A further object is to provide a simple circuit arrangement which willefifect the stoppage of the motor and will prevent itstarting againuntil the circuit is deliberately reestablished.

Extensive search and study has disclosed the urgent need to devise asafety device which would offer optimum protection to operators ofmechanized files of this type. Existing devices had size, distance,-anddirectional limitations which, even when extensively modified, would notanswer the purpose. 1 I

Guided by the theoryof simplicity, we have developed a 'new and uniquedevice to achieve the above objects. Basically this inventioninvolvesa'grounded cable disposedunder tension closelyadj'acent one or morecharged In a particular form the cable is centered within slightlyoversize holes in electrically charged .plates- .-Any contact-madebetween the cable and the plates will result in quickly stopping themachine through the intermediary of associated contacts and circuitrelays and connections. Preferably the cable is held in a taut line by aconstant spring pressure by specific means later described.

The simplicity of construction and operation of this device results in ahigh degree. of reliability. The grounded cable being fully encircledwill operate when the slightest pressure is applied from any direction.This safety mechanism overcomes the length limitations normallyencountered in other devices, and. operates with equal sensitivity alongits entire length.

The present preferred form of the invention is illus- 'trated in thedrawings, of which,

FIG. 1 is a partial perspective view of the top of a file casing withthe upper front cover removed to show the trays therein in the referenceposition and with the safety switch in position with respect thereto;

FIG. 2 .is a perspective exploded view of the details of the'switch andits mounting;

' FIG. 3 is aview showing the local circuit involving the safety switch;and

FIG. 4 is a view showing the circuit for the entire mechanized fileincluding the safety switch.

In FIG. 1 is shown the file casing 30 with the upper front cover removedto expose the trays 32 in the socalled reference position 31 where thetrays and their contents are available to the operator either forexamination or removal of the trays. It is understood that, inaccordance with well known practice, these trays are mounted on conveyormeans which moves them either up or down in an endless path and that,upon actuation Patented Feb. 19, 19133 of proper buttons or similardevices, designated trays may be thus presented. The side portions 33and 34 of the casing form chambers within which are housed the specificmeans for supporting the safety switch.

As shown the safety switch includes an elongated substantially rigidtubular element 35 of insulating material constituting a manual pressurebar extending between the side portions 33 and 34 of the casing andacross in front of the reference position as shown. This element 35embraces an elongated bare wire 36 of conductive material which extendsbetween bracket members 37 and 38 disposed within the side portions 33and 34 of the casing. The bracket members 37 and 38 are suitablygrounded on the casing of the machine. The wire 36 passes through anopening 39 in the bracket 38 and is fixed to the bracket 38 in anysuitable manner not shown. At the other end the wire is connected to aslideable metallic stem 40 movable within a sleeve 41 in the bracket3-7. The stem has a headed portion 43 between which and the sleeve 41 isdisposed a coiled spring 42 which tends to stretch the wire 36 and holdit under desired tension to maintain it taut.

As shown in FIG. 2 there is an insulated block 44 bolted to the cornerof the side portion 34 and there is a similar block similarly fixed tothe corner of the side portion 33 but not shown in FIG. 2. To theseblocks 44 are respectively fastened conductive plates 45 and 46. Theseplates 45 and 46 are connected in circuit in a manner to be explainedlater. Each plate is provided .with an aperture 47 through which thewire 36 passes but not normally in contact therewith. A slit 48 extendsfrom the aperture 47 in each plate to the adjacent edge thereof. Theportion of the plate beneath the slit may be bent aside suflicient topermit the wire 36 to he slipped into the aperture 47 and then movedback to close the opening thus formed.

This constitutes the main feature of the invention and it is obviousthat if the operator is careless in extending his hand into the openingin the casing, especially when the trays are in motion, he may sufferconsiderable injury. However if his hand makes even the slightestcontact with the tube 35 the wire 36 will be moved to make contact withthe plates 45 and 46 with the result that the motor of the device willbe stopped in a manner now to be described.

As shown in FIG. 3, the actuating circuit of the safety switch consistsof a relay BR having a low voltage mag netic coil, a pair of normallyclosed contacts BR-l operated by relay BR and connected in series withthe magnet coils of the motor-control relays U and D; a set of transfercontacts having normally closed contacts BR-Z in series with a greenpilot light, shown in the complete electrical diagram of FIG. 4, andnormally open contacts BR-3 connected from one terminal of a low voltagetransformer for example, 6 volts through a reset switch RS to terminal 9of the BR magnet coil. There is a pair of normally open contacts U-2operated by the magnet coil of relay U and a similar pair of contactsD-Z operated by magnet coil of relay D, said last named contacts beingconnected in parallel so as to form part of the series electricalcircuit (when closed) from a terminal of the transformer through thesafety switch contacts (when closed) through closed contacts U-Z or D-2to relay BR and back to the other side of the transformer. The holdingcircuit consists of a pair of normally closed contacts RS forming partof a series circuit from terminal 6 of the transformer through RS,normally open contacts BR-3 (when closed) and relay BR magnet coil toterminal 7 of the transformer.

The indicator or pilot light circuit consists of a circuit from terminal6 of the transformer through switch RS,

d normally closed relay contacts BR-Z and through the green light toterminal 7 of the transformer.

Operation of the Device FIG. 4 shows a typical complete circuit for amachine of this kind, and includes the safety switch described withrespect to FIG. 3. In FIG. 4 the safety switch is indicated by theletters FSS. Since we are not concerned with all the details of thecomplete circuit, it will only be described in general and onlyparticularly in respect to how the safety switch affects it. When thedevice isready for operation the upper front panel is opened as-shown inFIG. 1 thus exposing the card trays which are in the reference positionas well as the safety switch as shown. If it is desired to move thetrays in the lip-direction a start button and'the up button are pressedwhich will energize the motor and close the contacts U-Z o f'the relayU. This will establish a circuit through relay BR up to the safetyswitch FSS. When the machine is ready to start all the auxiliaryinterlock switches FPS, BPS, CS, F85, and HCS are open. With the machineat rest contacts U-2 and D-2 on the corresponding relays are open, asare contacts B-1 and Zen relay BR since there is no closed electricalpath from one side of the transformer secondary through magnet coil BRto the other side of the transformer. However, relay contacts BR-2 areclosed and thus the green light is lit by connection from terminal 7 ofthe transformer through the lamp, contacts BR-2, reset contacts RS toterminal 6 of the transformer.

When the conveyor is operated in either direction, down or up, bydepression of the appropriate buttons, relay contacts D-2 or U-Zrespectively are closed. If, during this operation period, contacts FSSof the safety switch are closed by the operators hand a closedelectrical circiut will exist from terminal 6 of the transformer,through safety switch contacts FSS, closed contacts U-2 or D-2 and BRmagnet coil to terminal 7 of the transformer. The magnet BR coil beingenergized will cause normally closed contact BR-l to open, thus removingelectrical power from the magnet coil of relay U or D. This willdeenergize the motor and apply dynamic braking to instantly stop theapparatus. Actuation of the magnet coil BR also causes norr'n'allyclosed contacts BR-2 to open, thus causing the green light to beextinguished. Also, normally open contacts BR-3 are caused to close,completing an electrical circuit from ter' minal 6 of the transformerthrough reset switch RS, contacts BR-3 and relaymagnet coil BR toterminal 7 of the transformer. Thus relay BR is held in actuatedcondition through its own contacts until such time that the reset switchRS is manually opened. The electrical holding circuit is then disruptedand the relay BR reverts to normal deenergized condition.

While the invention herein has been fully described in detail withrespect to a present preferred form which the invention may assume, itis not to be limited to the specific form shown since changes andmodificatoins may be made in the structure and parts without departingfrom the spirit and scope of the invention in its broadest aspects.Hence it is desired to cover any and all forms and modifications of theinvention which may come Within the spirit and scope of any one or moreof the appended claims.

What we claim as our invention, is:

1. A safety device for a mechanized file wherein a pinrality of traysare moved by a motor and motor controlled circuit meansiwithin a casingprovided with an opening permitting access to the trays, comprising agrounded wire extending across the opening, yieldably adjustable meansfor holding the wire taut, and an electrically charged plate in saidcircuit means disposed closely adjacent said Wire for deenergizing themotor control circuit to stop the motor when said wire is moved againstthe resistance of said holding means and into contact with said plate.

2. The safety device of claim 1 in which the charged plate has anopening through which the wire passes but out of contact with the edgeof said opening.

3. A safety device for a mechanized file wherein a plurality of traysare moved by a motor and motor controlled circuit means within a casingprovided with an opening permitting access to the trays, comprising agrounded wire associated with said circuit means and extendingcompletely across said opening, adjustable means for yieldably holdingsaid wire taut, a substantially rigid manual pressure bar extending thelength of the wire in said opening and constituting an insulating sleevefor said wire, and a plurality of electrically charged platesassociated-with the circuit means-and' disposed closely adjacent saidwire and arranged in-spaced'relation therealong for deenergizing themot-or'control circuit to stop the motor when said wireris moved againstthe resistance of said holding means and into contact with n plate.

4. The safety deviceiof claim 3 in which the charged plates each have anopening through which the wire passes but normally out of'contact wtihthe edges thereof.

5. The safetydevice of claim 3 in which the casingincludes side portionsat opposite ends of the opening, the wire.v extending into said sideportions, the adjustable yielding means for holding t-hewire taut beingdisposed in one of said side portions, each of saidplates having anopening larger than the diameter of the wire and through which the wirepasses and said openings being slotted to provide means for initiallypositioning thewirc in said openings.

6. Safety switch means for a mechanizedfile having a casing having anopening in which trays of cards are moved by a circuit controlled motor,a conductive wire extending across said opening, a substantially rigidmanual pressure bar extending the length of the wire in said opening andconstituting an insulating sleeve for said wire, oppositely spacedcharged plates each'having an opening through which the wire passeswithout contacting the same, yieldably adjustable means for holding thewire taut for free passage through said plateopenings, relayswithcontacts to close the. motor circuit when operated, a control relayin circuit with said contacts when they are closed, said controlrelaybeing energized when the conductive wire contacts acharged'plate,and a contact operated by the control relay and in circuit with thefirst mentioned relays to open the circuit of said relays and open themotor control circuit.

7. The safety switch means of claim 6 including a pilot 2 light normallyin circuit with another normally closed contact of the control relay andstill another normally open contact controlled by the control relay toestablish a holding circuit for said control relay when the lastmentioned contact is closed, and a reset switch normally closed and insaid holding circuit, said reset switch when opened breaking the holdingcircuit and permitting the relays-and contacts to restore to normalcondition.

References Cited in thefile of this patent- UNITED STATES PATENTS OTHERREFERENCES The Remington-Rand Conve-Filer Pamphlet, March 1952, page 3.

1. A SAFETY DEVICE FOR A MECHANIZED FILE WHEREIN A PLURALITY OF TRAYSARE MOVED BY A MOTOR AND MOTOR CONTROLLED CIRCUIT MEANS WITHIN A CASINGPROVIDED WITH AN OPENING PERMITTING ACCESS TO THE TRAYS, COMPRISING AGROUNDED WIRE EXTENDING ACROSS THE OPENING, YIELDABLY ADJUSTABLE MEANSFOR HOLDING THE WIRE TAUT, AND AN ELECTRICALLY CHARGED PLATE IN SAIDCIRCUIT MEANS DISPOSED CLOSELY ADJACENT SAID WIRE FOR DEENERGIZING THEMOTOR CONTROL CIRCUIT TO STOP THE MOTOR WHEN SAID WIRE IS MOVED AGAINSTTHE RESISTANCE OF SAID HOLDING MEANS AND INTO CONTACT WITH SAID PLATE.